JPH05198659A - Plasma processor - Google Patents

Abstract

PURPOSE:To simplify movement and a structure of a wafer transferring robot in a plasma processor. CONSTITUTION:A cassette mount base 3 has a screw shaft 14 to be rotated by a motor 13 and disposed in a post 12 erected on a base 11. An elevation member 16 is engaged with the shaft 14 and vertically moved up or down by the rotation of the shaft 14. The rotation of a motor 19 fixed to the outside of a gear box 18 on a lower surface of the member 16 is transmitted to a worm gear 23 in the box 18 through a drive pulley 20, a timing belt 21 and a driven pulley 21, the rotation of the worm 23 is further transmitted to a worm gear 24 engaged with the worm 23 to rotate a shaft 25 of the gear 24. A plate 27 is screwed at the shaft 25 and so set as to be directed toward a reaction chamber by the drive or the motor 19.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a plasma processing apparatus for transferring a wafer between a cassette and a reaction chamber (wafer holder) by a robot.

[0002]

2. Description of the Related Art As a plasma processing apparatus for automatically performing processing such as etching and ashing on the surface of a silicon wafer, a cassette containing a large number of unprocessed wafers vertically separated from a standby position along a transfer line. The wafer is transferred to a transfer position, and then the cassette is transferred to a mounting table, and the robot is transferred from the cassette fixed on the mounting table to the wafer holder one by one or a plurality of wafers. There is one that is put in a reaction chamber to perform a predetermined treatment.

The above wafer transfer is performed only by the movement of the robot arm while the cassette is fixed. That is, the robot arm extends and the wafer at the bottom of the cassette is placed on the robot hand.
The arm is contracted and horizontally rotated by a predetermined angle (180 °), the arm is extended again, the hand is inserted into the wafer holder and the wafer is transferred to the holder, and then the arm is contracted and horizontally rotated by a predetermined angle and the arm is moved by one step. Is raised and the same movement is repeated to transfer all the wafers.

Further, the above-mentioned cassette is an integrally molded plastic product, and its structure is as shown in FIG.
Two parallel side plates 101, 101 are erected on the upper side, and a groove 1 into which the peripheral edge of the wafer W enters the inner side surfaces of these side plates 101.
02 ... is formed.

[0005]

In the above-described conventional plasma processing apparatus, the reaction chamber is often not located on the extension line of the side plate of the cassette fixed to the mounting table, and in particular, two reaction chambers are provided. In the plasma processing apparatus, the extension line of the side plate and the reaction chamber are displaced from each other.

On the other hand, when the robot hand enters the cassette, the side plate and the hand must move so as not to interfere with each other. As a result, the movement of the wafer transfer between the robot and the cassette and the movement of the wafer transfer between the robot and the wafer holder do not become symmetrical, which makes the structure of the robot extremely complicated. However, the delivery time cannot be shortened.

If the direction of the cassette is directed to the reaction chamber when the direction of the transfer line is changed or the cassette is set on the transfer line, the above disadvantage can be solved, but there are two or more reaction chambers. In such cases, such means cannot be adopted.

[0008]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention does not fix a mounting table for receiving a wafer cassette from a transfer line, but rotates between a direction orthogonal to the transfer line and a direction facing the reaction chamber. It was possible to move.

[0009]

The cassette that has traveled along the transfer line is moved and fixed on the mounting table at the transfer position. Then, the mounting table is rotated in the horizontal plane to the direction toward the reaction chamber, and as a result, the reaction chamber is positioned on the extension line of the side plate of the cassette.

[0010]

Embodiments of the present invention will be described below with reference to the accompanying drawings. FIG. 1 is an overall plan view of a plasma processing apparatus according to the present invention. In the plasma processing apparatus, a transfer line 2 including a belt conveyor is provided along a main body 1, and the main body 1 is arranged along the transfer line 2. Two cassette mounting tables 3 and 3, two reaction chambers 4 and 4 arranged corresponding to these cassette mounting tables 3 and 3, and an intermediate position between these cassette mounting tables 3 and 3 and reaction chambers 4 and 4. It consists of a transfer robot 5.

The transfer line 2 transfers the cassette 6 containing the unprocessed wafer W from the standby station S1 to the transfer position S.
2 and S2, and the cassette 6 is transferred to and from the mounting table 3 at the transfer position S2.

The reaction chamber 4 is made of synthetic quartz, and a wafer holder 7 is provided below it. This wafer holder is provided with a large number of grooves into which the peripheral edge of the wafer W fits inside four pillars made of synthetic quartz, and can be moved up and down to enter the reaction chamber 4 at the upper limit position. The bottom opening of the reaction chamber 4 is closed with.

The transfer robot 5 has an articulated arm 9 rotatable about a vertical axis 8 in a horizontal plane, and a hand 10 for mounting a wafer W is provided at the tip of the arm 9.

Next, details of the mounting table 3 will be described with reference to FIGS. 2 is a plan view of the mounting table, FIG. 3 is a sectional view taken along the line AA of FIG. 2, and FIG. 4 is a view in the direction of arrow B of FIG. The screw shaft 14 rotated by the motor 13 is arranged in the column 12, and the lifting member 16 is engaged with the rail 15 provided on the side wall of the column 12 and attached to the lifting member 16. The nut 17 is screwed onto the screw shaft 14 so that the lifting member 16 can be moved up and down by the rotation of the screw shaft 14.

A gear box 18 is provided on the lower surface of the lifting member 16.
The rotation of the motor 19 fixed to the outside of the gear box 18 is driven by the drive pulley 20 and the timing belt 21.
Also, the rotation of the worm 23 is transmitted to the worm 23 in the gear box 18 via the driven pulley 22, and the rotation of the worm 23 is transmitted to the worm gear 24 meshing with the worm 23 to rotate the shaft 25 of the worm gear 24.

The upper end of the shaft 25 projects from an opening 26 formed in the elevating member 15, a plate 27 is screwed to the upper end, a stopper 28 is attached to the lower surface of the plate 27, and a gear train is driven by the motor 19. When the plate 27 is horizontally rotated by a predetermined angle, the stopper 28 comes into contact with the limit switch 29 attached to the elevating member 15 to cut off the power supply to the motor 19 and stop the rotation of the plate 27. In the present invention, the plate 27 is set to face the reaction chamber 4 at this stopped position.

Further, an opening 30 is formed in the plate 27, and a sensor 31 for detecting whether or not the wafer W remains in the cassette 6 placed on the plate 27 is exposed from the opening 30.

In the above, in order to perform the plasma processing on the wafer W, the cassette 6 is moved from the standby position S1 to the transfer line 2.
Along to the transfer position S2, and at the transfer position S2, the cassette 6 is transferred onto the plate 27 of the mounting table 3, and then the motor 19 is driven to move the plate 27 to the reaction chamber facing the transfer robot 5. Rotate until it faces 4. By this operation, the reaction chamber 4 is positioned on the extension line of the side plate of the cassette 6, and when the arm 9 of the robot 5 expands and contracts, it does not interfere with the side plate of the cassette 6.

Then, the arm 9 of the robot 5 extends into the cassette 6 fixed on the plate 27, the wafer W at the lowest stage in the cassette is placed on the robot hand 10, and the arm is contracted and horizontally rotated by 180 °. , The arm 9 is extended again, the hand 10 is inserted into the wafer holder 7, and the wafer W
To the holder 7, and then the arm 9 contracts
The arm is raised by one step as it horizontally rotates, and the same movement as described above is repeated to hold all the wafers W.
The wafer W is moved together with the holder 7 into the reaction chamber 4 and the wafer W is placed in the reaction chamber 4 to generate a vacuumed plasma to perform a predetermined process. When the process is completed, the reverse operation is performed. Then, the wafer W is returned to the cassette 6, and then the cassette 6 is returned to the transfer line 2 and sent to the next step.

In the illustrated example, two mounting tables 3 and two reaction chambers 4 are provided. Therefore, for example, the rotation angle of the plate 27 when transferring the wafer W from the mounting table 3 on the right side to the reaction chamber 4 on the right side becomes a problem. In this case as well, the wafer W is transferred to the reaction chamber 4 on the left side. The plate 27 is rotated as much as the time. In this way, the expansion and contraction movements of the arm of the robot 5 become exactly the same, and only the rotation angle of the arm 9 on the horizontal plane needs to be changed, and the control becomes simple.

[0021]

As described above, according to the present invention,
Since the mounting table that receives the wafer cassette from the transfer line is rotatable between the direction orthogonal to the transfer line and the direction facing the reaction chamber, the reaction chamber is located on the extension line of the side plate of the cassette. As a result, the movement of the wafer transfer between the robot and the cassette and the movement of the wafer transfer between the robot and the wafer holder are the target movements, which simplifies the movement and structure of the robot. The cost can be reduced and the delivery time can be shortened.

[Brief description of drawings]

FIG. 1 is an overall plan view of a plasma processing apparatus according to the present invention.

FIG. 2 is a plan view of a mounting table.

3 is a sectional view taken along the line AA of FIG.

4 is a view in the direction of arrow B in FIG.

FIG. 5 is a perspective view of a wafer cassette.

[Explanation of symbols]

2 ... conveying line, 3 ... mounting table, 4 ... reaction chamber, 5
... Transfer robot, 6 ... Cassette, 7 ... Wafer holder, 1
1 ... Base, 16 ... Elevating member, 27 ... Plate, W ... Wafer.

Claims (2)

[Claims] 1. A cassette mounting table for transferring a cassette containing wafers to and from a transfer line, a reaction chamber for performing various kinds of processing on a wafer in a plasma atmosphere, and a wafer transfer between the reaction chamber and the cassette. In a plasma processing apparatus equipped with a robot for performing loading and retracting arms, the mounting table is rotatable between a direction orthogonal to the transfer line and a direction facing the reaction chamber. Processing equipment. 2. The plasma processing apparatus according to claim 1, wherein the mounting table can be moved up and down intermittently.